# CVE-2026-101059: utcp-http before 1.1.4 OAuth2 tokenUrl Trust Boundary Bypass

> Attackers can redirect OAuth2 credential submissions to malicious endpoints by providing unvalidated token URLs in OpenAPI specifications.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 27 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** GHSA-r549-qqpm-phj8

## What is CVE-2026-101059?

CVE-2026-101059 is a high-severity server-side request forgery vulnerability in universal-tool-calling-protocol python-utcp, published on 27 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

utcp-http before 1.1.4 fails to validate the OAuth2 tokenUrl field from remote OpenAPI specifications, allowing attackers to redirect credential submission to arbitrary endpoints. When a victim registers an attacker-controlled OpenAPI spec and invokes a generated OAuth2-protected tool, the library POSTs the victim's client_id and client_secret to the attacker-supplied token endpoint without URL validation.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-101059?


## How do I fix CVE-2026-101059?

No fix has been published for CVE-2026-101059 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-101059 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-101059 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-101059 and fix it if it is affected.

What it is: CVE-2026-101059 is a high-severity server-side request forgery vulnerability in universal-tool-calling-protocol python-utcp, published on 27 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-101059 exists.

Affected product: universal-tool-calling-protocol python-utcp. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-101059/ (Markdown: https://insights.sbomify.com/CVE-2026-101059/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-101059
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-101059
- OSV: https://osv.dev/vulnerability/CVE-2026-101059

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-101059/
Summaries are generated and may contain mistakes; the official description above is the record.